Editor's Note: Timothy Shriver, the chairman of Special Olympics for the past 11 years, co-produced the 1997 DreamWorks Studios movie "Amistad." His mother, Eunice Kennedy Shriver, the sister of Sen. Ted Kennedy, founded Special Olympics and his father, Sargent Shriver, served as president. Tim's sister Maria, the wife of California Gov. Arnold Schwarzenegger, is a Special Olympics board member. For another view, read here.

WASHINGTON (CNN) -- I am so proud of everyone who turned out to Monday's premiere of the film "Tropic Thunder" to protest its unfortunate and humiliating portrayal of people with intellectual disabilities.

Prior to the premiere, I joined a large coalition of individuals and organizations to engage in discussions with DreamWorks Studios CEO Stacey Snider and others from the studio to express our concern over the film's "Simple Jack" subplot and the slogans, "Once upon a time there was a retard," and "Never go full retard."

Members of the Coalition of National Disability Organizations -- disabled advocates and family members of people with intellectual disabilities -- have seen the movie and reported shock and disgust. Their reactions have resonated with many of us who take their cause and their voice with the utmost seriousness.

While I am disappointed that we were not consulted in the same manner as other minority groups depicted in the film and that there are 17 mentions of the "R-word" with one mention of the "N-word," I am grateful to Ms. Snider for listening to the coalition and for taking steps to eliminate some of the film's most offensive marketing elements.

I am also appreciative of her commitment to working in the future for an end to denigrating speech and hurtful portrayals of people with intellectual disabilities in film and in society. DreamWorks and its leaders have a powerful reputation for advancing socially and politically important issues.

In particular, Steven Spielberg has been a generous supporter of the work of Special Olympics, for which I am deeply grateful. I look forward to counting the hopes and dreams of 200 million people with intellectual disabilities among the causes of this formidable group of creative and artistic leaders.

Now, however, is the time to raise our voices against "Tropic Thunder" and the harm it is sure to visit on people with intellectual disabilities.

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Together with the members of the international coalition, I am asking Steven Spielberg, Stacey Snider, Ben Stiller and the entire "Tropic Thunder" team to stop showing the film, and asking movie theaters and moviegoers to shut this movie out. "Tropic Thunder" is a colossal blunder. Don't show or see "Tropic Thunder."

The degrading use of the word "retard" together with the broader humiliation of people with intellectual disabilities in the film goes way too far. When the R-word is casually bandied about and when bumbling, clueless caricatures designed to mimic the behavior of people with intellectual disabilities are on screen, they have an unmistakable outcome: They mock, directly or indirectly, people with intellectual disabilities. They perpetuate the worst stereotypes. They further exclusion and isolation. They are simply mean.

Mockery in any form, or for any purpose or directed at anyone, especially those least able to defend themselves, is neither funny nor acceptable. We must work together to bring it to an end. As chairman of the Special Olympics, I am inspired to be as vocal as possible about this important matter to effect positive change and to generate support for those who deserve our respect.

Ridicule is a subtle but malicious practice that only serves to exclude and marginalize people with intellectual disabilities. Stop "Tropic Thunder."

People with intellectual disabilities can be great athletes, productive employees, positive friends, courageous role models. Let's open our schools, doctors offices, businesses, communities, and most importantly, our hearts to the giftedness of every human being. No more exceptions. No more exclusion.

Some may think we ought to lighten up and not get so worked up because this is, after all, just a film. But films become part of pop culture and character lines are repeated in other settings time and time again. It's clear to me that lines from this particular film will provide hurtful ammunition outside the movie theatre. While I realize that the film's creators call this a parody and they never intended to hurt anyone, it doesn't mean those words won't.

How can you help? Ban the R-word. Ban the movie. Take a stand.

The opinions expressed in this commentary are solely those of the writer.